The invention is based on an internal combustion engine provided with combustion chambers, comprising a main combustion chamber and an ignition chamber, the latter being connected to the main combustion chamber by at least one spill port. In conventional internal combustion engines of this kind, there is the disadvantage, if the engines are operated with a fuel-air mixture which must be spark-ignited, that such fuel-air mixture, especially if it is maintained at a lean level, resists ignition in the ignition chamber, so that a non-uniform torque transmission of the internal combustion engine is produced. To obtain a sufficiently safe ignition and reaction of the operating media with one another at a minimum proportion of fuel, various methods have been employed. It is known in mixture-compressing internal combustion engines to provide for charge stratification, wherein a very lean mixture is introduced in a predominant quantity into the main combustion chamber while an ignition chamber, connected to the main combustion chamber by spill ports, is fed with a rich, ignitable mixture and the latter is ignited in this ignition chamber.
This application is related to the disclosure of Wossner U.S. Pat. No. 3,962,869, issued June 15, 1976; Feldman U.S. Pat. No. 3,604,503; and Grover U.S. Pat. No. 3,229,759, relating to heat pipes and heat transfer devices and the like which are incorporated herein by reference.
In another known process, the internal combustion engine is operated with a single, lean primary mixture and additional fuel to enrich the primary mixture and to attain ignitability is injected in an ignition combustion chamber in communication with the main combustion chamber via spill ports or firing channels. These aforementioned devices are all very complicated and expensive. Moreover, it is furthermore known to provide a precombustion chamber connected to the main combustion chamber by way of a single spill port and to set the main mixture in the main combustion chamber into a directional rotary motion to produce a certain stratification of the mixture due to centrifugal action. The heavy, fuel-rich mixture is forced, during the compression stroke, into the prechamber via the spill port so that residual gases from the previous combustion process are forced back into the chamber and a mixture which is more ignitable due to stratification is formed in the zone of the spill port. This mixture is ignited at the point by a spark plug in the conventional system.
However, this system does not insure a sufficiently stable turbulence formation in the combustion chamber, since this swirl, produced during the intake stroke, must be maintained until the end of compression. Therefore, in order to provide for a safe ignition process, it is still necessary to provide a mixture relatively greatly enriched with fuel, especially also during the warm-up period.
The arrangement of the spark plug in the spill zone has the disadvantage that a great deal of conversion of the fuel-air mixture takes place in the prechamber and, in addition to a reduction in the engine efficiency, the prechamber as well as the spark plugs are placed under a high thermal load. Also, it is impossible in this device to conduct measures improving the ignitability, as suggested in another patent application, such as an increase and control of the temperature of the prechamber wall to the close proximity of the point of auto ignition, and the correlation of the ignition spark, if the operating media are subject to spark ignition, with a non-turbulent laminar wall stream having a minimal flow velocity.